How to configure OpenVPN to use WiKID Strong Authentication

These instructions describe setting up two-factor authentication with WiKID Strong Authentication, which is a commercial/open source two-factor authentication system and OpenVPN, an SSL-encrypted VPN, on a Linux server using the Radius Pluggable Authentication Module.. First, we will configure PAM to use Radius, then we will configure OpenVPN to use PAM and one-time passwords, then we will create a network client on the WiKID server for OpenVPN. We won't go into specifics about installing these services, rather we will focus on configuring them to all work together.